Excavating-cutter.



PATENTED MAY 8,

J. B. CANTWELL.

BXCAVATING GUTTER.

APPLwATIoN FILED Mmm, 1905.

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JOHN BURKE O ANTVELL, OF WATERTOVN, NEV YORK.

ExoAvATlNG-CUTTER.

Specification of Letters Patent.

ratented May 8` 1906.

Application filed March 8, 1905. Serial No. 249,032.

To @ZZ whom it ,may concern:

Be it known that I, JOHN BURKE CANT- WELL, a citizen of the UnitedStates, residing at I/Vatertown, in the county of Jefferson and State ofNew York, have invented certain new and useful Improvements inExcavating-Cutters7 of which the following is a specification, referencebeing had therein to the accompanying drawings. I

The invention relates to excavating apparatus, and has more particularreference to the construction of rotary cutter which subdivides the soilpreparatory to its removal by suction or other suitable means.

The invention consists in the peculiar construction and arrangement ofthe cutterblades, as hereinafter set forth.

In the drawings, Figure 1 is a cross-section through the rotary cutter.Fig. 2 is an elevation of one of the cutter-blades7 and Fig. 3 is across-section on line :E of Fig. l.

As shown, the rotarycutter is designed to be arranged at the end of asuction-pipe through which a current of water is drawn, carrying thematerial severed by the cutter. Where the excavator is working in clayor relatively hard soil, it is desirable that it should be subdividedinto comparatively small pieces to prevent the clogging of thesuction-pipe. To this end the rotary cutter is provided not only withlongitudinally-extending severing-blades, but also cross-cutters whichsubdivide the strips severed by the longitudinal blades.

In detail, Arepresents the longitudinal cutter-blades, which arepreferably of segmental form and at their opposite ends are bent to formradially-extending portions B and B,

- which latter are attached to suitable heads C and C upon a rotar shaftD. This shaft, as shown, passes axia ly through the suctionpipe E,through which the material severed is carried away. The blades A arespaced around the rotary heads C and O and are inclined to the radiallines of said head, so as to form a favorable angle for cutting. Thusthe forward sharpened edge a will in the rotation of the heads severstrips from the soil, which are deiiected inward and into the spaceinclosed by the blades and into direct connection with the suction-pipe.These strips severed by the blades A are further subdivided bycross-cutters F of the following construction: The cutters F aredesigned to subdivide the strips severed by the blades A Withoutmaterially increasing the resistance to the movement of the cutterthrough the soil. Inasmuch as the resistance to the cutter increases inproportion-to the distance of the cutting edge from the axis of rotationit is desirable to place the cross-cutters F as near as possible to saidaxis of rotation and at the same time to be in a position to subdividethe strips severed by the blades A. This is accomplished by securing theblades F to the inner sides of the blades A, and, as shown, each cutterF is provided with laterally-extending wings or securing-flanges I),which are riveted or otherwise secured to the blades A. The forward endsof the blades F preferably project slightly in advance of the edges a ofthe blades A, so that the soil will be slitted in advance of thesevering by the blades A. As shown, these forward edges c are rounded inthe plane of the blade and extend from the cutting edge a of the blade Ainto proximity to the rear edge d of the next adjacent blade A. Fromtheir forward portions the blades F taper rearwardly, preferablyextending to the rear edge d of the blades A. The forward edges of thewings b also preferably extend slightly in advance of the cutting edge aof the blades A and are sharpened to form cutting edges e.

Vith the construction as shown, in operation the rotation of the shaft Dand heads O C simultaneously with the pressing of the cutter into thesoil will cause the cutting edges c of the blades F to slit the surfaceof the soil, which is then severed into strips by the blades A, and theportions of the strips between the heads and cross-cutters F aredirected inward into the path of the water current drawn through thesuction-pipe E. By reason of the tapering shape of the blades Fconsiderable free space is provided within the cutter for carrying awaythe material, and at the same time these tapering portions reinforce theforward cutting edges c of the blades F. The cutting edges c and e atthe forward edge of the cross-cutters F extend to slightly beyond thecircular path of the cutting edges a, so that the resistance to therotatlon of the cutter is not materially increased by thesecross-cutters.

What I claim as my invention isl. The combination with a rotatingcutterblade extending substantially parallel to the axis of rotation, ofa cross-cutting blade secured to the aforesaid blade, wherezby the ma-IIO terial is slit by said cross-cutting blade and subsequently in thesame stroke severed by said longitudinal blade.

2. The combination with a rotary cuttingblade, extending substantiallyparallel to the axis of rotation, of a cross-cutting blade secured tothe aforesaid blade and extending inwardly therefrom.

3. The combination with a rotary cuttingblade, extending substantiallyparallel to the axis of rotation, of a blade extending transverse to theaxis of rotation, and inwardly from the cutting edge of saidlongitudinal blade.

4. The combination with a series of rotat ing blades arranged to extendsubstantially parallel to a common axis of rotation and inclining inwardtherefrom, cutting edges of a cross-cutting blade extending from thecutting edge of one of said longitudinal blades into proximity to therear edge of an adjacent longitudinal blade.

5. The combination with a series of rotating blades extendingsubstantially parallel to a common axis of rotation and spaced aboutsaid axis, of a cross-cutting blade for each of said longitudinalblades, extending inward therefrom, and arranged to slit the soil in advance of severance by the longitudinal blade, the cross cutters ofadjacent longitudinal blades being arranged in diHerent orbits ofrotation.

6. The combination with a series of rotating cutting-blades, spacedaround a common axis of rotation, and extending substantially paralleltherewith, of a cross-cutter for each blade arranged in a planetransverse to the axis and extending inward from the cutting edge of thelongitudinal blade at its forward cutting edge, and tapering toward therear end of said longitudinal blade.

7. The combination of the rotary longitudinal cutter A, of thecrosscutter F secured to the inner side of said blade by lateral wingsor securing-flanges b, having the curved cutting edge c, vand thetapering rearward portion, for thepurpose described.

8. The combination with a rotating cutterblade extending substantiallylongitudinally of the axis of rotation, of a cutting-blade secured tothe aforesaid blade at an angle thereto, so positioned that theircombined action in the same cutting stroke severs strips of material oflesser length than said longitudinal blade.

9. The combination with a rotating cutterblade extending substantiallylongitudinally of the axis of rotation, of means secured to said bladewhereby the material is subdivided before being severed by said blade inthe same stroke.

In testimony whereof I affix my signature in presence of two witnesses.

JOHN BURKE CANTWELL.

Witnesses C. O. HERVEY, THEO. A. JAEGER.

